## Force

Have you ever heard of force? Force is a push or pull on an object which causes objects to move. Force is a vector because it has both size and direction. Force can be weak or strong. The SI unit for force is newton. One object can have more than one force at the same time.In fact all objects on Earth have at least two forces acting on them at all times. Those forces are gravity and upward force. The combined force on any object are called net force. When the two force acting on an object in opposite direction, if the opposing force is unbalanced then the net force will be greater than zero. If the opposing force is balance then the net force will be zero meaning that if one side has a greater force then the object will move to that side but two forces can act on an object in the same direction.

Throughout the lesson, I felt like I understand a lot and it can also be applied to real life what I’m doing daily. I think it’s one of the interesting lessons to learn in my round 5. Sometimes, we met this kind of action many time but we never realize that it’s all connect to lessons of science. I would really love to focus and paying more attention to the lesson that I’m going to learn next year.

## Solution/ STEM

For this round, we have learn many interesting topic such as solution, motion and force. One of my favorite topic is solution which I’m going to talk about.

In a simple meaning of solution is a mean of solving a problem or dealing with a difficult situation.  In chemistry, solution means a form of one substance dissolve in another. For example rock dissolve in water form a solution. When a substance dissolve in another is called solute. The  substance that let the solute dissolve in is called solvent. For example ocean water is a solution which solute is salt that dissolve in solvent; water. In this example solid dissolve in liquid. However, matter in any state can be solute or solvent. Whenever solute dissolve in solvent it will change to the same state as the solvent. If the solute and solvent already in the same state, it will present greater quantity is considered to be solvent.

In a solution there are three rate of dissolving. First is stirring. Stirring is one of several factor that affect how fast the solute dissolve in solvent. Second is temperature, temperature is another factor. A solid solute dissolve faster in a higher temperature. For example sugar dissolve faster in hot coffee than iced coffee. The third one is  the surface area of the solute.

In this round, I feel like I’ve learn a lot from the lesson and I feel more confidence in asking question to my falcilitator. I feel like I’ve improve a lot in learning. I hope to learn more interesting topic in STEM. It’s quite challenging for me but I think I can handle it.

## Carbon

Carbon is one of the main topic that we focus on in STEM class for this round. Carbon is a nonmetal element. Carbon has four valence electron. So, it need four more electron in order to complete its outer energy level. In order to achieve this it need covalent bond that is form between nonmetal which they share a pair of electron. Usually, carbon form bond with hydrogen. There are three types of bond of carbon with other carbon atoms. Those bond are single, double and triple bond. Single bond is when they share a pair of electron. Double bond is when they share two pairs of bond and triple bond is when they share three pairs of bond. The types of single bond are called Alkane. The type of double bond are called Alkene and the type of triple bond are called Alkyne.

We also learned about hydrocarbon. Hydrocarbon are compounds that contain only carbon and hydrogen. There are two types of hydrocarbon which are saturated hydrocarbon and unsaturated hydrocarbon. Saturated hydrocarbon contain only single bond which is alkane type. The name of alkane is always end with “ane”.The first part of the name indicates how many carbon atom each has. The smallest is called Methane which has only one carbon atom. The next are Ethane, Propane, Butane, Pentane, Hexane, Heptane, Octane, Nonane and Decane.

This are the list with molecular formula

Unsaturated carbon can be double or triple bond which are Alkene or Alkyne. The type of Alkene is always end with “ene”. The type of Alkyne is always end with “yne”. It’s also indicates to how many carbon atom each has.

Overall, I feel it been a great round for me. I think I has understand a lot more about STEM. Also, I feel more confidence in asking question and has increase my passion in STEM. I hope to see more challenge and fun in the next round.

## STEM/ Round 2

In STEM class I’ve learned a lot, but for this round, we mainly focus on periodic table and chemical bond. We still use the same website which is CK-12.

The first person who creates a periodic table is Mendeleev. There are 118 elements in the periodic table. At that time Mendeleev has arranged the elements by its atomic mass. Atomic mass is the mass of protons and neutrons in the atom. For nowadays people use a modern periodic table which they have arranged the elements by its atomic number. Atomic number is the number of protons in an atom of an element. There also a chemical symbol to represent the element which consists of one or two letter that comes from the chemical’s name in English or other languages. For example, the symbol of lead is Pb which come from a Latin word plumbum.

They also divide the elements into three types which are metals( blue), metalloids or semimetals (orange), and nonmetals (green). The rows on the periodic table called period and the columns of the periodic table are called groups. Some period of the modern periodic table are longer than others you can see the first have only two elements and the period 6 and 7 its contrast so long that some of their elements are placed below the main part of the table. As you can see most of the element are metals. Metals are the elements that are good at conductor of electricity and a relatively high melting point. So, almost all at the room temperature. They are the largest of the classed in the modern periodic table. Most of the metal are also good conductors of heats. Nonmetal are the elements that do not conduct electricity, poor conductors of heat and it is the second largest classes of the elements. Nonmetals generally have properties that are opposite of those metals. Metalloids is the element that in between metals and nonmetals. Metalloid has some properties of metals and some properties of nonmetals. For example, many metalloids can conduct electricity but only at a certain temperature and these metalloids are called semiconductors.

There also some groups of the element which are Alkali metal, Alkaline Earth  Metal, Halogen and Noble gas. Alkali Metal has just only one valence electrons which are highly reactive. Alkali Metal is the most reactive of all the metals. Most of Alkali Metal is soft which enough to cut with knife. Alkali metal has also low density. Alkaline Earth Metal is the elements that is in group two. They have two valence electrons. They also very reactive but not like alkali metals. They are harder and denser than the alkali metal. Groups 3-12 are called Transition Metals. Transition have more valence electron and less reactive than metal and the first two groups metals. They are shiny, very hard, high melting points and boiling points. Halogens are all the elements that in the group 17. They are highly reactive nonmetal and with 7 valence electrons. Halogen group include gas, liquid and solid and they react violently with alkali metals. The last group is Noble gas. The nonmetal elements that in groups 18 are called Noble gas group. They are the least reactive group because their outer energy level is full and they are colorless odorless gases.

## In STEM

In STEM I’ve learned a lot of thing such as chemistry, energy, weather, matter, astronomy and etc…. For this few we mainly focus on matter and also we dig a little into chemistry. The website that our facilitator use to teach and read is called CK12. This website is really helpful to me because it explains in very detail and it uses a lot of examples to explain to us. I can learn it and understand more about it by myself without facilitator just to read. I’ve learned many things from and matter. Matter defined anything that has mass and volume. There are two properties in the matter which are physical properties and chemical properties. Chemical properties are the properties of matter that can be measured or observe only when changes form and become something else. Physical properties are the properties that can be measured and observed without matter changing to different substances. One interesting thing about mass and weight that most people make their mistake of saying those word. So mass is the amount of matter in substance or object and its unit called Kilogram but the weight is a measure of the force of gravity pulling on an object and its unit known as Newton. So you should say your mass is 62 kg not your weight is 62 kg. Don’t be confused!!!.

One more thing that I’ve to learn about atoms which are related to the STEM. Atom is the smallest particle of an element that still has an element of the property.

So in the matter, there is the element, the element there are atoms, an atom, there are nucleus and electron and in the nucleus, there are proton and neutron. You might wonder what proton and neutron made from. Well, proton and neutron made quark and electron made from leptin. That’s is most of the thing that I’ve learned so far in STEM class. Hope you enjoy!!